Sparking plug for internal combustion engines



E. T. BUNT April 28, 1936.

SPARKING PLUG FOR INTERNAL COMBUSTION ENGINES Filed April 5, 1954 RTZ ONLQH T F N N EB m WE w. '5 A E T A W Patented Apr. 28, 1936 NITED sr'rss SPARKING PLUG FOR INTERNAL COMBUSTION ENGINES Edward Trezise Bunt, Bristol, England, assignor of one-half to Frank Edwin John Hill, Bristol,

England Application April 3, 1934, Serial No. 718,753 In Great Britain December 15, 1933 2 Claims.

This invention relates to sparking plugs for internal combustion engines, including those of the Diesel type, its object being to keep the electrodes clean adjacent the sparking point, by preventing or minimizing the deposition thereon of particles of soot, oil, or scale, which is frequently the cause of misfiring.

According to the invention one or both of the electrodes, and/or a device associated therewith, is or are adapted to rise and fall together or separately at each cycle of operations of the engine, under the influence of pressure conditions in the combustion chamber, or other causes. Either or both the electrodes, or an electrode and the said associated device, may rotate or oscillate during the rising and falling movement. One or both of the electrodes may have a swinging movement, an axial straight line movement relatively to the body of the plug, or a movement transverse to the axis of the said body, the said movements being obtained by means of a hinge, pivot, slide, slot, or other convenient means. Thereby any deposits which might otherwise accumulate about the electrodes will be dispersed.

In order that the said invention may be clearly understood and readily carried into effect, the same will now be described with reference to the accompanying drawing.

Figure 1 represents a positive electrode in which a double arm is so pivoted between upper and lower stops on the electrode pin that the said arm, in addition to rising and falling, can swing in a vertical plane and is free to rotate in a horizontal plane.

Figure 2 is a plan of the underside of the plug containing the electrodes arranged as in Figure 1.

Figure 3 is a plan of the underside of a plug in which both electrodes are movable.

Figure 4 represents in elevation, partly in central vertical section, a plug in which the negative electrode is a movable rod.

Figure 5 is a plan of the underside of the plug represented in Figure 4.

In all the figures A indicates the positive elec trode or central pin and B the negative electrode.

In the arrangement according to Figures 1 and 2 the lower part of the central pin A is screwthreaded; a nut a is first secured thereon, then an associated device in the form of a double arm a is placed under the said nut, the said arm having a hole therein of such size as to provide a clearance between the arm and the screw-threaded portion of the electrode, and then another nut a is fitted on the electrode to prevent detachment of the arm a The arm a is thus free to rise and fall bodily between the two stop nuts,

to swing up and down, and also to rotate around the central pin A In this case the negative electrode is formed as a fixed part of the body of the plug, which latter is hollowed out to a greater distance than usual from the central pin.

Referring to Figure 3, the movable arm a on the central electrode is combined with a movable ring B In this case the fixed supporting arms D may be taken to represent the negative electrode, and the ring B and arm at as devices associated respectively with the negative and positive electrodes.

Referring to Figures 4 and 5, the negative electrode B is a rod fitting loosely in holes I) bored in the hollow part of the plug body, so that it can rotate, rise and fall, or move to and from the centre line of the electrode A. The lower end of the latter may be tapered or flattened, or may be placed slightly out of centre in relation to the hollow part of the plug body. The holes 19 may be inclined so that the distance of the rod B from the nearest part of the electrode A, that is, the spark gap, except for slight variations remains unaltered during movement of the rod B.

What I claim and desire to secure by Letters Patent of the United States is:

l. A sparking plug including a negative electrode consisting of a ring of small radial crosssection relatively to its diameter, freely supported to rise and fall in relation to the central electrode and to rotate around the axis of said central electrode, in combination with a two-armed member loosely carried on said central electrode to rise and fall in relation to said central electrode, said member being also adapted to rotate in a substantially horizontal plane and to rock in a substantially vertical plane about said central electrode.

2. A sparking plug including a central electrode screw-threaded upon its lower portion, a negative electrode consisting of a ring of small radial cross-section relatively to its diameter, said ring being freely supported to rise and fall in relation to said central electrode and to rotate around the axis of said central electrode, a twoarmed member loosely carried on said central electrode and free to move in any direction thereon, and two nuts engaging the screw threaded lower portion of said electrode and serving as individual stops to limit the movements of said two-armed member, the lower one of said nuts also preventing the two-armed member from falling out of the plug.

EDWARD TREZISE BUN T. 

